1.\" Copyright (c) 2011 Kai Wang
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25.\" $Id: dwarf_def_macro.3 3644 2018-10-15 19:55:01Z jkoshy $
26.\"
27.Dd November 9, 2011
28.Dt DWARF_DEF_MACRO 3
29.Os
30.Sh NAME
31.Nm dwarf_def_macro
32.Nd add a macro definition to a DWARF producer instance
33.Sh LIBRARY
34.Lb libdwarf
35.Sh SYNOPSIS
36.In libdwarf.h
37.Ft "int"
38.Fo dwarf_def_macro
39.Fa "Dwarf_P_Debug dbg"
40.Fa "Dwarf_Unsigned lineno"
41.Fa "char *name"
42.Fa "char *value"
43.Fa "Dwarf_Error *err"
44.Fc
45.Sh DESCRIPTION
46Function
47.Fn dwarf_def_macro
48adds a macro definition to a DWARF producer instance.
49.Pp
50Argument
51.Ar dbg
52should reference a DWARF producer instance allocated using
53.Xr dwarf_producer_init 3
54or
55.Xr dwarf_producer_init_b 3 .
56.Pp
57Argument
58.Ar lineno
59specifies the line number of the source line where the macro is
60defined.
61A line number of zero is used for macros that are defined
62before any source file is read.
63.Pp
64Argument
65.Ar name
66should point to a NUL-terminated string containing the name
67of the macro.
68For function-like macros this parameter should also include
69parentheses and parameter names if any.
70.Pp
71Argument
72.Ar value
73should point to a NUL-terminated string containing the value
74of the macro.
75If the macro does not have a value, argument
76.Ar value
77should be set to NULL.
78.Pp
79If argument
80.Ar err
81is not NULL, it will be used to store error information in case of an
82error.
83.Sh RETURN VALUES
84On success, function
85.Fn dwarf_def_macro
86returns
87.Dv DW_DLV_OK .
88In case of an error, function
89.Fn dwarf_def_macro
90returns
91.Dv DW_DLV_ERROR
92and sets the argument
93.Ar err .
94.Sh EXAMPLES
95To record the fact that a macro named
96.Dv _STDIO_H_
97was defined at line 20 of the current macro file, use:
98.Bd -literal -offset indent
99Dwarf_P_Debug dbg;
100Dwarf_Error de;
101
102/* ... Assume 'dbg' refers to a DWARF producer instance... */
103if (dwarf_def_macro(dbg, 20, "_STDIO_H_", NULL, &de) != DW_DLV_OK)
104	errx(EXIT_FAILURE, "dwarf_def_macro failed: %s",
105	    dwarf_errmsg(-1));
106.Ed
107.Sh ERRORS
108Function
109.Fn dwarf_def_macro
110can fail with:
111.Bl -tag -width ".Bq Er DW_DLE_ARGUMENT"
112.It Bq Er DW_DLE_ARGUMENT
113Either arguments
114.Ar dbg
115or
116.Ar name
117was NULL.
118.It Bq Er DW_DLE_MEMORY
119An out of memory condition was encountered during the execution of the
120function.
121.El
122.Sh SEE ALSO
123.Xr dwarf 3 ,
124.Xr dwarf_end_macro_file 3 ,
125.Xr dwarf_producer_init 3 ,
126.Xr dwarf_producer_init_b 3 ,
127.Xr dwarf_start_macro_file 3 ,
128.Xr dwarf_undef_macro 3 ,
129.Xr dwarf_vendor_ext 3
130